Re: The lost formula  Printable Version + HP Forums (https://archived.hpcalc.org/museumforum) + Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum1.html) + Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum2.html) + Thread: Re: The lost formula (/thread177165.html) 
Re: The lost formula  John B. Smitherman  01172011 We don't know what we don't know.
John
Re: The lost formula  Martin Pinckney  01172011 If anyone understands the meaning of this thread, I would like to know.
Re: The lost formula  Norman Dziedzic  01172011 Seems to me like just a question of curve fitting. A thermistor is an electronic device whose resistance changes with temperature in a predictable, albeit nonlinear, way. See:http://www.vishay.com/doc?29053
I'm guessing the OP used to have a simple equation to approximate a particular thermistor response at one time and lost it.
Re: The lost formula  Martin Pinckney  01172011 Thanks for responding, Norman. Quote: That much I got.
Quote:The rest not so much. Re: The lost formula  lost in translation  Norman Dziedzic  01172011 I think I had my high pass filter on and didn't absorb that part of the thread ;/
Re: The lost formula  Walter B  01172011 Martin,
let me explain. As far as I understood the OP, he
If that behaviour is of practical relevance, it was solved in the time between  or it can be modeled easily by some brute force fitting algorithm using the tools available today, which where beyond imagination decades ago. So the OP's problem is most probably solved now either way by the advancement of science ... dona eo pacem! HTH. I'm most willing, however, to delete my two postings in this thread if they will cause any trouble whatsoever ...
Re: The lost formula  Martin Pinckney  01172011 Walter, I think I've got it now. Thanks for your help.
No need to delete anything.
Re: The lost formula  designnut  01182011 I think I probably started adding 273 to the C temperature and found that was not quite the right slope and adjusted from there. I'll give it a try through programming and see what happens. I know it was dirt simple, probably a temp addon and a normalizing factor to suit the particular resistance thermistor. Sam
Re: The lost formula  Pal G.  01182011 Quote:
42.
Re: The lost formula  Martin Pinckney  01182011 Now that explains it!
Re: The lost formula  Walter B  01182011 Don't lose your towel, ask Douglas Adams instead ;)
Re: The lost formula  Dan W  01182011 When I first discovered WolframAlpha, I had to ask it the question of life, the universe, and everything.
It came up with the correct answer. ;)
